1. Field of the Invention
The present invention relates to an accumulator package for a hand-held power tool such as, e.g., an accumulator-driven screw-driving tool, drilling tool, or wood-machining tool. The accumulator package includes a housing having a plurality of accumulator cells provided therein and a connection element electrically connected with the accumulator cells and accessible from outside. There is further provided a charge state display for displaying a charge state of the accumulator cells and which is actuated by outer switch means accessible from the outside.
With such accumulator packages the charge state can be ascertained each time by actuation of the outer switch means, e.g., in order to be able to charge the accumulator by a suitable time.
2. Description of the Prior Art
German Utility model DE 295 15 860 U1 discloses an accumulator package with an integrated charge state display. The charge state display is actuated by a push-button that projects outwardly through a side of the accumulator package housing.
The use of a push-button for actuating the charge state display, as needed, prevents an additional discharge of the accumulator cells by an actuated charge state display during extended idle or stop time.
The drawback of the known accumulator package consists in that the push-button, in particular because it projects through the housing, increases manufacturing costs and creates sealing problems. In addition, with such an accumulator package, in many applications, there exists a danger of the outwardly projecting push-button being broken off. Further, with the use of such a charge state display which is actuated as needed, it often happens that the operator forgets from time to time to check the charge state. As a result, a suitable moment for charging the accumulator package can be missed, in consequence of which the operator must interrupt a certain operational cycle at an unfavorable time in the operation to charge the accumulator package.
German Publication DE 42 04 420 A1 discloses an accumulator-driven electrical tool with the charge state display pinned on the accumulator package. The charge state display includes an LCD-display that permanently displays the charge state, and two light-emitting diodes a respective one of which lightens up upon actuation of the electrical tool in order to show whether the charge state is sufficient or too small for the actual tool adjustments.
The drawback of the accumulator package described above lies in that the LCD-display leads to a continuous additional discharge which becomes particularly noticeable at long stoppage periods. On the other hand, the light-emitting diodes are actuated in connection with the electrical tool.
Accordingly, an object of the present invention is to provide an accumulator package for a power tool in which the above-described drawbacks are eliminated.
Another object of the present invention is to provide an accumulator package in which in addition to the prevention of the unnecessary discharge, a repeated testing of the charge state is ensured.